and science editor reviews how young women may put themselves in harm's way. >> reporter: it's convenient say many young women. >> it's probably the most convenient place to put it especially when you go out. you put your money on one breast and the phone in the other. >> it's easy to feel the vibration and someone texts you, you can get the call really fast. >> reporter: maybe they should talk to tiffany france. her mother had misgivings. >> we never took it seriously until after she was diagnosed. >> reporter: tiffany got breast cancer at 21. >> it just so happened her tumors were exactly where her cell phone had been against her skin, her bare skin for about six years. >> reporter: surgeons removed tiffany's left breast. >> it's kind of coincidental it's right where i kept my cell phone are. >> reporter: the dots are where her humors developed and the doctor says it exactly matched her cell phone. this image shows the tumors were just under the surface of her skin. >> all in this area right here. which is where i tuck my cell phone. >> reporter: jane said she did that for ten years.